Numeric keypads are commonly found in handheld electronic devices which may not be able to incorporate a QWERTY keyboard due to size constraints. These devices may include, for example, mobile phones, media players, remote controls and so forth. The increasing number of communication functions incorporated in the aforementioned devices, such as, for example, instant messaging, short string messaging and the like has led to a need for text input using these numeric keypads.
A common way to input text using a numeric keypad is the “multi-tap” method where keys 2 to 9 are labeled with the letters A-Z in a way that every key is labeled with either 3 or 4 letters. In order to enter text, letters can be typed by activating the corresponding key repeatedly. For example, key 6 is labeled with the letters “MNO”. A single key press leads to an M, a double key press results in an N while pressing the key three times produces the letter O. While this method is commonplace, it is undeniable that it requires a high level of dexterity for a user's fingers and is also rather tedious.
Another common method of inputting test using a numeric keypad relates to Predictive Text Input systems. In this method, the desired word/phrase is proposed from an initial sequence of single key presses. For example, if the key 2 is pressed twice and the key 3 is pressed once, then words like “BET, BELL, BETTER” and so forth may be suggested. However, the accuracy of such systems is questionable especially when entering names, addresses and abbreviations, and may hamper rather than improve text input.